1. Field of the Invention
The invention lies in the field of crop protection compositions which can be used against weeds in tolerant or resistant crops of soybeans and other leguminous species, for example beans, peas and lentils, and comprise, as active herbicidal ingredients, a combination of two or more herbicides.
2. Description of Related Art
The introduction of tolerant or resistant soybean and leguminous species and lines, especially of transgenic soybean and leguminous species and lines, supplements the conventional weed control system with novel active ingredients which are non-selective per se in conventional soybean and leguminous species. The active ingredients are, for example, known broad spectrum herbicides such as glyphosate, sulfosate, glufosinate, bialaphos and imidazolinone herbicides, which can now be used in the crops which have been developed to be tolerant to each of them. The efficacy of these herbicides against weeds in the tolerant crops is at a high level, but—similarly to other herbicide treatments—depends on the nature of the herbicide used, the application rate thereof, the respective formulation form, the weeds to be controlled in each case, the climatic and soil conditions, etc. In addition, the herbicides have weaknesses (gaps) with respect to specific species of weeds. A further criterion is the duration of action or the degradation rate of the herbicide. Attention should also be paid to any changes in the sensitivity of weeds which can occur in the case of prolonged use of the herbicides or in a geographically limited manner. Losses of action in the case of individual plants can be balanced out only to a relative degree, if at all, by higher application rates of the herbicides. Moreover, there is still a need for methods of achieving the herbicidal action with a lower application rate of active ingredients.
One means of improving the use profile of a herbicide may consist in the combination of the active ingredient with one or more other active ingredients which contribute the desired additional properties. However, in the case of the combined use of several active ingredients, it is not a rare event for phenomena of chemical, physical and biological incompatibility to occur, for example inadequate stability of a coformulation, decomposition of an active ingredient or antagonism of the biological action of the active ingredients. In contrast, desirable combinations of active ingredients are those with a favorable action profile (action level, compatibility), high stability and possible synergistic enhancement of action, which allows reduction of the application rate compared to the individual application of the active ingredients to be combined.